Shearing device



Aug. 16, 1938. D. R. MURPHY SHEARING DEVICE Filed Nov. 11, 1937 2Sheets-sheaf, l

' INVENTOR DAN R. MURPHK wq'm ATTORNEYS.

Aug. 16, 1938. D. R. MURPHY SHEARING DIEVICE Filed Ndv. 11, 1957 2Sheets-Sheet 2 INVENTOR. 174 R. MUIPPHK ATTORN EYS.

Patented Aug. 16, 1938 UNITED STATES SHEARING DEVICE Dan R. Murphy,,Middletown,

The American Rolling Mill town, Ohio, a corporation of Ohio, assignor toCompany, Middle- Ohio Application November 11, 1937, Serial No. 174,093

10 Claims.

My invention relates to shearing devices for shearing what are referredto in the trade as circles from square blanks, and more particularly itrelates to an attachment which may be added to a conventional rotaryshearing device for the purpose of enabling such devices to cut perfectcircles.

In the cutting of circles from square blanks. it is, of course,necessary to get the cutting edges onto the proper line of cut, whichmay be a slight distance from the edge of the blank. In the past. thishas been done in one of two ways; either the cooperating cutting edgesof the shear have been separated and the blank inserted therebetween andthe cutting edges then brought together on the line of cut, or the blankwas simply shoved against the cutting elements, which then cut into thedesired line of cut from the edge of the blank.

Both of these alternatives have disadvantages. The operation of openingthe cutting elements to admit the blank is relatively slow and consumesvaluable time, while if the. other alternative is used. the finishedcircle is not truly circular, but has a slight flat place adjacent thepoint where the line of cut passes to'the proper circumference of thecircle.

With the above difiiculties in mind, it is an object of my invention toprovide a device which is extremely simple and relatively cheap tomanufacture, which will permit the cutting of perfect circles fromsquare blanks.

It is a further object of my invention to provide such devices which maybe attached to a conventional rotary shear without d fllculty.

Another obiect of my invention is the provision of a device as aboveoutlined. which will cut circles from square blanks without leaving afiat place on the circumference and without increasing the time of theoperation.

These and other objects of my invention which will be apparent to oneskilled in the art upon reading these specifications, or which will bepointed out hereinafter. I accomplish by that certain construction andarrangements of parts of which I shall now describe an exemplaryembodiment.

Reference is made to the drawings forming a part hereof and in which:

Figure 1 is a plan view of a blank shown in its relation to a clampingelement, a side stop, and cutting element.

Fig. 2 is an elevational view of a rotary shear embodying my invention.

Fig. 3 is a detailed cross sectional view on an enlarged scale of thatpart of Fig. 2 to which my invention particularly relates.

-Referring now to Fig. 2, I have shown somewhat diagrammatically a moreor less conventional rotary shear comprising a frame 30, having a baseextension M. The frame 30 carries the parallel shafts 3 and 4, which,respectively, carry the rotary knives 5 and 6. The shafts 3 and It mayor may not be geared together, as desired. A pulley l is provided on theshaft 3 for driving the same from any suitable source of power. In viewof the fact that it may be necessary to bring the knives 5 and t closertogether as they become worn, the shaft 3 is provided with a pivotedbearing indicated generally at 9. A screw, provided with a handleindicated generally at 3, is provided for the purpose of raising andlowering the right hand end of the shaft 31. For the purpose ofproviding for relative axial adjustment of the knives, the shaft e isprovided with clamping nuts indicated generally at I and ii, cooperatingwith a portion of the frame 30, whereby the knife 6 may be moved towardthe right or left with respect to the knife 5.

Mounted in ways in a conventional manner upon the base extension it is atable l2. The table i2 is provided with a nut i5, adapted to cooperatewith a threaded portion of the shaft M. The shaft it may be turned bymeans of a handwheel it for the purpose of adjusting the position of thetable E2 on the base 36 with respect to the knives and 6.

Referring now more particularly to Fig. 3, the table i2 carries asupporting member I9 pivoted thereon by means of a stud at 58. Theposition of the member i9 may be fixed upon the table by means of thenut and bolt arrangement indicated enerally at 32.

A clamping member indicated generally at H, and comprising upper andlower clamping jaws Ila and Nb, is mounted in ways 33 on the member l9,so that after the position of the table I 2 has been set, furthermovement toward and away from the cutting knives is provided by movementof the member ll in the ways 33. The member H has threaded into it, apiston rod 34 which is attached to a piston 28 in the cylinder 26, whichis fixedly mounted upon the member ill. The limit of movement toward theleft of Fig. 3 is provided by abutment of the hub portion of the piston2i against the cylinder head a. The limit of movement of the pistontoward the right of Fig. 3 is fixed by the position of the limit screw22.

The cylinder 20 may be pneumatic and if so, will be connected to asuitable source of pressure and provided with suitable valves. Anexemplary ings.

limit of movementtoward the left is indicated by the broken linerepresenting the left-hand edge of the member ll in its furthestposition toward the left. In Fig.4, this movement is represented by thebroken circular line representing the positions of the upper jaw I'Ia.

In Fig. I, the blank is indicated at l and an appropriate disappearingside stop is indicated at 2. The arrow indicates the direction ofrotation.

The operation of my device will be apparent from what has been saidabove. A blank I to be cut to circular form is placed between the jaws11a and I'll), which are then tightened by any conventional arrangementsuch as is indicated generally at 35. The table 12 is adjusted towardthe left until the edge of the blank touches the" shearing point of theknivesi and 6. The knives are then set into rotation by any suitablemeans and air is admitted to the right-hand end of the cylinder 20,whereby the clamping member I1 is urged toward the left as indicated inthe draw- Of course, the machine will be so set up that when the memberI! is in its extreme lefthand position, the cutting point of the knives5 and 6 will be on the desired circumference of the finished circie.- Asthe knives rotate and out, they of course, feed the blank rotatably.

It will be understood that modifications may be made in my inventionwithout departing from the spirit of it.

Having thus described my invention, what I claim as new and desire tosecure by Letters P atent is:- 1-. In a circular-shearing device, abase'fa pair of rotary knives mounted on said base, a table" mounted onsaid base in such manner that the distance between said table and saidknives may be varied, a clamping device slidably mounted on said table,and means urging said clamping device toward said knives.

2. In a circular shearing device, a base, a pair of rotary knivesmounted on said base, a table mounted on said base in such manner thatthe distance between said table and said knives may be varied, aclamping device slidably mounted on said table, means for urging saidclamping device toward said knives, and means limiting the extent ofsaid slidable movement.

3. In a circular shearing device, a base, a pair of rotary knivesmounted on said base, a table mounted on said base in such manner thatthe distance between said table and said knives may be varied, aclamping device slidably mounted on said table, pneumatic means forurging said clamping device toward said knives, and means limiting theextent of said slidable movement toward said knives.

4. In a circular shearing device, a base, a pair of rotary knivesmounted on said base, a table mounted on said base in such manner thatthe distance between said table and said knives may be varied, aclamping device slidably mounted on said table, pneumatic means forurging said clamping device toward said knives, said last mentionedmeans comprising an air cylinder and a piston therein attached to saidclamping device, the abutment of said piston against the head end of thecylinder serving to limit the extent of the slidable movement towardsaid knives.

5. In a circular shearing device, a base, a pair of rotary knivesmounted onisaid base, a table mounted on said base in such manner thatthe distance between said table and said knives may be varied, aclamping device slidably mounted on said table, pneumatic means forurging said clamping' device toward said knives, said last mentionedmeans comprising an air cylinder and a piston therein attached to saidclamping device, the abutment of said piston against the head end of thecylinder serving to limit the extent of the slidable movement towardsaid knives, and means for limiting the movement of said clamping deviceaway from said knives.

6. In a circular shearing device, a base, a pair of rotary knivesmounted on said base, a table mounted on said base in such manner thatthe distance betweensaid table and said knives may be varied, a clampingdevice slidably mounted on said table, pneumatic means for urging said.clamping device toward said knives, means limiting the extent of saidslidable movement toward said knives, and means for limiting themovement of said clamping device away from said knives.

, device toward said knives.

8. In a circular shearing device, a base, a pair of rotary knivesmounted on said base, a table mounted on said base in such manner thatthe distancebetw'een said table and said knives may table, a clampingdevice slidably mounted on said support, pneumatic means for urging saidclamping device toward said knives, and means limiting the extent ofsaid slidable movement toward said knives.

9. In a circular shearing device, a base, a pair of rotary knivesmounted on said base, a table mounted on said base in such manner thatthe distance between said table and said knives may be varied, a supportpivotally mounted on said table, a clamping device slidably mounted onsaid support, pneumatic means for urging said clamping device towardsaid knives, said last mentioned means comprising an air cylinder and apiston therein attached to said clamping device, the abutment of saidpiston against the head end of the cylinder serving to limit the extentof the slidable movement toward said knives.

10. In a circular shearing device, a base, a pair of rotary knivesmounted on said base, a table mounted on said base in such manner thatthe distance between said table and said knives may be varied, a supportpivotally mounted on' said table, a clamping device slidably mounted onsaid support, pneumatic means for urging said clamping device towardsaid knives, said last mentioned means comprising an air cylinder and apiston therein attached to said clamping device, the abutment of saidpiston against the head end of the cylinder serving to limit the extentof the slidable movement toward said knives, and means for limiting themovement of said clamping device away from said knives.

DAN R. MURPHY.

be varied, a support'pivotally mounted on said"

